Induced intra- and intermolecular template switching as a therapeutic mechanism against RNA viruses.

Viral RNA-dependent RNA polymerases (RdRps) are a target for broad-spectrum antiviral therapeutic agents. Recently, we demonstrated that incorporation of the T-1106 triphosphate, a pyrazine-carboxamide ribonucleotide, into nascent RNA increases pausing and backtracking by the poliovirus RdRp. Here, by monitoring enterovirus A-71 RdRp dynamics during RNA synthesis using magnetic tweezers, we identify the "backtracked" state as an intermediate used by the RdRp for copy-back RNA synthesis and homologous recombination. Cell-based assays and RNA sequencing (RNA-seq) experiments further demonstrate that the pyrazine-carboxamide ribonucleotide stimulates these processes during infection. These results suggest that pyrazine-carboxamide ribonucleotides do not induce lethal mutagenesis or chain termination but function by promoting template switching and formation of defective viral genomes. We conclude that RdRp-catalyzed intra- and intermolecular template switching can be induced by pyrazine-carboxamide ribonucleotides, defining an additional mechanistic class of antiviral ribonucleotides with potential for broad-spectrum activity.

Interfering with nucleotide excision by the coronavirus 3'-to-5' exoribonuclease.

Some of the most efficacious antiviral therapeutics are ribonucleos(t)ide analogs. The presence of a 3'-to-5' proofreading exoribonuclease (ExoN) in coronaviruses diminishes the potency of many ribonucleotide analogs. The ability to interfere with ExoN activity will create new possibilities for control of SARS-CoV-2 infection. ExoN is formed by a 1:1 complex of nsp14 and nsp10 proteins. We have purified and characterized ExoN using a robust, quantitative system that reveals determinants of specificity and efficiency of hydrolysis. Double-stranded RNA is preferred over single-stranded RNA. Nucleotide excision is distributive, with only one or two nucleotides hydrolyzed in a single binding event. The composition of the terminal basepair modulates excision. A stalled SARS-CoV-2 replicase in complex with either correctly or incorrectly terminated products prevents excision, suggesting that a mispaired end is insufficient to displace the replicase. Finally, we have discovered several modifications to the 3'-RNA terminus that interfere with or block ExoN-catalyzed excision. While a 3'-OH facilitates hydrolysis of a nucleotide with a normal ribose configuration, this substituent is not required for a nucleotide with a planar ribose configuration such as that present in the antiviral nucleotide produced by viperin. Design of ExoN-resistant, antiviral ribonucleotides should be feasible.

Sedentary and physical activity time differs between self-reported ATLS-2 physical activity questionnaire and accelerometer measurements in adolescents and young adults in the United Arab Emirates.

BACKGROUND: Most young adults and adolescents in the United Arab Emirates (UAE) do not meet the established internationally recommended physical activity levels per day. The Arab Teen Lifestyle Study (ATLS) physical activity questionnaire has been recommended for measuring self-reported physical activity of Arab adolescents and young adults (aged 14 years to mid-twenties). The first version of the ATLS has been validated with accelerometers and pedometers (r ≤ 0.30). The revised version of the questionnaire (ATLS-2, 2021) needs further validation. The aim of this study was to validate the self-reported subjective sedentary and physical activity time of the ATLS-2 (revised version) physical activity questionnaire with that of Fibion accelerometer-measured data. METHODS: In this cross-sectional study, 131 healthy adolescents and young adults (aged 20.47 ± 2.16 [mean ± SD] years (range 14-25 years), body mass index 23.09 ± 4.45 (kg/m2) completed the ATLS-2 and wore the Fibion accelerometer for a maximum of 7 days. Participants (n = 131; 81% non-UAE Arabs (n = 106), 13% Asians (n = 17) and 6% Emiratis (n = 8)) with valid ATLS-2 data without missing scores and Fibion data of minimum 10 h/day for at least 3 weekdays and 1 weekend day were analyzed. Concurrent validity between the two methods was assessed by the Spearman rho correlation and Bland-Altman plots. RESULTS: The questionnaire underestimated sedentary and physical activity time compared to the accelerometer data. Only negligible to weak correlations (r ≤ 0.12; p > 0.05) were found for sitting, walking, cycling, moderate intensity activity, high intensity activity and total activity time. In addition, a proportional/systematic bias was evident in the plots for all but two (walking and moderate intensity activity time) of the outcome measures of interest. CONCLUSIONS: Overall, self-reported ATLS-2 sedentary and physical activity time had low correlation and agreement with objective Fibion accelerometer measurements in adolescents and young adults in the UAE. Therefore, sedentary and physical activity assessment for these groups should not be limited to self-reported measures.

Sensorimotor integration, cervical sensorimotor control, and cost of cognitive-motor dual tasking: Are there differences in patients with chronic whiplash-associated disorders and chronic idiopathic neck pain compared to healthy controls?

PURPOSE: The current investigation aimed to compare the sensorimotor integration, sensorimotor control, and cost of cognitive-motor dual task during walking, in persons with chronic WAD as compared to matched chronic idiopathic neck pain and normal healthy controls. METHODS: A cross-sectional, case control design comparing 30 participants in each of two study groups (chronic WAD and chronic idiopathic neck pain) to a matched control group was conducted. Measurements included: (1) the cranio-vertebral angle (CVA), (2) left and right rotation head repositioning accuracy (HRA), (3) frontal N30 amplitudes to assess sensorimotor integration, (4) dual cognitive gait cost (DCGC). RESULTS: A statistically significant difference for the CVA was found between groups: WAD 36.8° ± 3.4, chronic pain 44.5° ± 1.5, and controls 47.1° ± 4; p < 0.05. MANOVA revealed significant group differences for the N30 amplitude (p < 0.05), where the WAD group had the greatest amplitude. Statistically significant differences among the three groups were found for HRA left and right where the WAD group had the greatest error, (p < 0.05). Post hoc tests revealed that the WAD group had the highest dual-task cost during walking, (p < 0.05). Significant linear correlations between the CVA and N30 amplitude, HRA, and DCGC were identified in all 3 groups, (p < 0.05). CONCLUSIONS: Compared to both a matched control group and chronic neck pain group, whiplash-injured persons have greater forward head posture, greater error in sensorimotor control, and an altered ability to perform a motor task with a simultaneous cognitive task.

Comparative effects of tensioning and sliding neural mobilization on peripheral and autonomic nervous system function: A randomized controlled trial.

Background: Although different types of neural mobilization (NM) exercises induce different amounts of longitudinal nerve excursion and strain, the question whether the increased longitudinal stress and nerve excursion from sliding or tensioning intervention may subtly affect the neural functions has not been answered yet. Objective: To compare the effects of tensioning NM versus sliding NM of the median nerve on peripheral and autonomic nervous system function. Methods: In this randomized controlled trial, 90 participants were randomly assigned to tensioning NM, sliding NM, or sham NM. The neurophysiological outcome measures included peak-to-peak amplitude of the dermatomal somatosensory evoked potential (DSSEP) for dermatomes C6, C7, C8, and T1. Secondary outcome measures included amplitude and latency of skin sympathetic response. All outcome measures were assessed pretreatment, immediately after the two weeks of treatment and one week after the last session of the treatment. Results: A 2-way repeated measures ANOVA revealed significant differences between the three groups. The post hoc analysis indicated that tensioning NM significantly decreased the dermatomal amplitude for C6, C7, C8, and T1 ( p < 0 . 005 ). Sympathetic skin responses in the gliding NM group showed lower amplitudes and prolonged latencies post-treatment when compared to tensioning NM group ( p < 0 . 05 ). In contrast, no significant changes were observed in the DSSEPs and skin sympathetic responses for participants in the sham treatment group ( p > 0 . 05 ). Conclusions: A tensioning NM on the median nerve had a possible adverse effect on the neurophysiology variables of the nerves involved in the neural mobilization. Thus, tensioning NM with the current parameters that place increased stress and strain on the peripheral nervous system should be avoided.

Restoring cervical lordosis by cervical extension traction methods in the treatment of cervical spine disorders: a systematic review of controlled trials.

[Purpose] To systematically review the literature on the use of cervical extension traction methods for increasing cervical lordosis in those with hypolordosis and cervical spine disorders. [Methods] Literature searches for controlled clinical trials were performed in Pubmed, PEDro, Cochrane, and ICL databases. Search terms included iterations related to the cervical spine, neck pain and disorders, and extension traction rehabilitation. [Results] Of 1,001 initially located articles, 9 met the inclusion/exclusion criteria. The trials demonstrated increases in radiographically measured lordosis of 12-18°, over 5-15 weeks, after 15-60 treatment sessions. Untreated controls/comparison groups not receiving extension traction showed no increase in cervical lordosis. Several trials demonstrated that both traction and comparison treatment groups experienced immediate pain relief. Traction treatment groups maintained their pain and disability improvements up to 1.5 years later. Comparative groups not receiving lordosis improvement experienced regression of symptoms towards pre-treatment values by 1 years' follow-up. [Conclusion] There are several high-quality controlled clinical trials substantiating that increasing cervical lordosis by extension traction as part of a spinal rehabilitation program reduces pain and disability and improves functional measures, and that these improvements are maintained long-term. Comparative groups who receive multimodal rehabilitation but not extension traction experience temporary relief that regresses after treatment cessation.

Restoring lumbar lordosis: a systematic review of controlled trials utilizing Chiropractic Bio Physics® (CBP®) non-surgical approach to increasing lumbar lordosis in the treatment of low back disorders.

[Purpose] To systematically review controlled trial evidence for the use of lumbar extension traction by Chiropractic BioPhysics® methods for the purpose of increasing lumbar lordosis in those with hypolordosis and low back disorders. [Methods] Literature searches were performed in Pubmed, PEDro, CINAHL, Cochrane, and ICL databases. Search terms included iterations related to the lumbar spine, low back pain and extension traction rehabilitation. [Results] Four articles detailing 2 randomized and 1 non-randomized trial were located. Trials demonstrated increases in radiographic measured lordosis of 7-11°, over 10-12 weeks, after 30-36 treatment sessions. Randomized trials demonstrated traction treated groups mostly maintained lordosis correction, pain relief, and disability after 6-months follow-up. The non-randomized trial showed lordosis and pain intensity were maintained with periodic maintenance care for 1.5 years. Importantly, control/comparison groups had no increase in lumbar lordosis. Randomized trials showed comparison groups receiving physiotherapy-less the traction, had temporary pain reduction during treatment that regressed towards baseline levels as early as 3-months after treatment. [Conclusion] Limited but good quality evidence substantiates that the use of extension traction methods in rehabilitation programs definitively increases lumbar hypolordosis. Preliminarily, these studies indicate these methods provide longer-term relief to patients with low back disorders versus conventional rehabilitation approaches tested.

Rational Control of Poliovirus RNA-Dependent RNA Polymerase Fidelity by Modulating Motif-D Loop Conformational Dynamics.

The conserved structural motif D is an important determinant of the speed and fidelity of viral RNA-dependent RNA polymerases (RdRps). Structural and computational studies have suggested that conformational changes in the motif-D loop that help to reposition the catalytic lysine represent critical steps in nucleotide selection and incorporation. Conformations of the motif-D loop in the poliovirus RdRp are likely controlled in part by noncovalent interactions involving the motif-D residue Glu364. This residue swivels between making interactions with Lys228 and Asn370 to stabilize the open and closed loop conformations, respectively. We show here that we can rationally control the motif-D loop conformation by breaking these interactions. The K228A variant favors a more active closed conformation, leading to increased nucleotide incorporation rates and decreased nucleotide selectivity, and the N370A variant favors a less active open conformation, leading to decreased nucleotide incorporation rates and increased nucleotide selectivity. Similar competing interactions likely control nucleotide incorporation rates and fidelity in other viral RdRps. Rational engineering of these interactions may be important in the generation of live, attenuated vaccine strains, considering the established relationships between RdRp function and viral pathogenesis.

Triphosphate Reorientation of the Incoming Nucleotide as a Fidelity Checkpoint in Viral RNA-dependent RNA Polymerases.

The nucleotide incorporation fidelity of the viral RNA-dependent RNA polymerase (RdRp) is important for maintaining functional genetic information but, at the same time, is also important for generating sufficient genetic diversity to escape the bottlenecks of the host's antiviral response. We have previously shown that the structural dynamics of the motif D loop are closely related to nucleotide discrimination. Previous studies have also suggested that there is a reorientation of the triphosphate of the incoming nucleotide, which is essential before nucleophilic attack from the primer RNA 3'-hydroxyl. Here, we have used 31P NMR with poliovirus RdRp to show that the binding environment of the triphosphate is different when correct versus incorrect nucleotide binds. We also show that amino acid substitutions at residues known to interact with the triphosphate can alter the binding orientation/environment of the nucleotide, sometimes lead to protein conformational changes, and lead to substantial changes in RdRp fidelity. The analyses of other fidelity variants also show that changes in the triphosphate binding environment are not always accompanied by changes in the structural dynamics of the motif D loop or other regions known to be important for RdRp fidelity, including motif B. Altogether, our studies suggest that the conformational changes in motifs B and D, and the nucleoside triphosphate reorientation represent separable, "tunable" fidelity checkpoints.

Does improvement towards a normal cervical sagittal configuration aid in the management of cervical myofascial pain syndrome: a 1- year randomized controlled trial.

BACKGROUND: There is a growing interest concerning the understanding of and rehabilitation of the sagittal configuration of the cervical spine as a clinical outcome. However, the literature on the topic specific to conservative treatment outcomes of patients with chronic myofascial cervical pain syndrome (CMCPS) has not adequately addressed the relationship between cervical sagittal alignment and improved pain, disability and range of motion. METHODS: A randomized controlled study with a 1-year follow-up. Here, 120 (76 males) patients with chronic CMCPS and defined cervical sagittal posture abnormalities were randomly assigned to the control or an intervention group. Both groups received the Integrated neuromuscular inhibition technique (INIT); additionally, the intervention group received the denneroll cervical traction device. Alignment outcomes included two measures of sagittal posture: cervical angle (CV), and shoulder angle (SH). Patient relevant outcome measures included: neck pain intensity (NRS), neck disability (NDI), pressure pain thresholds (PPT), cervical range of motion using the CROM. Measures were assessed at three intervals: baseline, 10 weeks, and 1 year after the 10 week follow up. RESULTS: After 10 weeks of treatment, between group statistical analysis, showed equal improvements for both the intervention and control groups in NRS (p = 0.36) and NDI (p = 0.09). However, at 10 weeks, there were significant differences between groups favoring the intervention group for PPT (p<0.001) and all measures of CROM (p<0.001). Additionally, at 10 weeks the sagittal alignment variables showed significant differences favoring the intervention group for CV p<0.001 and SH (p<0.001) indicating improved CSA. Importantly, at the 1-year follow-up, between group analysis identified a regression back to baseline values for the control group for the non-significant group differences (NRS and NDI) at the 10-week mark. Thus, all variables were significantly different between groups favoring the intervention group at 1-year follow up: NRS (p<0.001), NDI (p<0.001), PPT p<0.001), CROM (p<0.001), CV (p<0.001), SH (p<0.001). CONCLUSION: The addition of the denneroll cervical orthotic to a multimodal program positively affected CMCPS outcomes at long term follow up. We speculate the improved sagittal cervical posture alignment outcomes contributed to our findings. TRIAL REGISTRATION: Pan African Clinical Trial Registry Clinical Trial Registry: PACTR201801002968301 , registered 11 January 2018 (retrospectively registered).

Sequence-Specific Fidelity Alterations Associated with West Nile Virus Attenuation in Mosquitoes.

High rates of error-prone replication result in the rapid accumulation of genetic diversity of RNA viruses. Recent studies suggest that mutation rates are selected for optimal viral fitness and that modest variations in replicase fidelity may be associated with viral attenuation. Arthropod-borne viruses (arboviruses) are unique in their requirement for host cycling and may necessitate substantial genetic and phenotypic plasticity. In order to more thoroughly investigate the correlates, mechanisms and consequences of arbovirus fidelity, we selected fidelity variants of West Nile virus (WNV; Flaviviridae, Flavivirus) utilizing selection in the presence of a mutagen. We identified two mutations in the WNV RNA-dependent RNA polymerase associated with increased fidelity, V793I and G806R, and a single mutation in the WNV methyltransferase, T248I, associated with decreased fidelity. Both deep-sequencing and in vitro biochemical assays confirmed strain-specific differences in both fidelity and mutational bias. WNV fidelity variants demonstrated host-specific alterations to replicative fitness in vitro, with modest attenuation in mosquito but not vertebrate cell culture. Experimental infections of colonized and field populations of Cx. quinquefaciatus demonstrated that WNV fidelity alterations are associated with a significantly impaired capacity to establish viable infections in mosquitoes. Taken together, these studies (i) demonstrate the importance of allosteric interactions in regulating mutation rates, (ii) establish that mutational spectra can be both sequence and strain-dependent, and (iii) display the profound phenotypic consequences associated with altered replication complex function of flaviviruses.

Structural models of mammalian mitochondrial transcription factor B2.

Mammalian mitochondrial DNA (mtDNA) encodes 13 core proteins of oxidative phosphorylation, 12S and 16S ribosomal RNAs, and 22 transfer RNAs. Mutations and deletions of mtDNA and/or nuclear genes encoding mitochondrial proteins have been implicated in a wide range of diseases. Thus, cell survival and health of the organism require some steady-state level of the mitochondrial genome and its expression. In mammalian systems, the mitochondrial transcription factor B2 (mtTFB2 or TFB2M) is indispensable for transcription initiation. TFB2M along with two other proteins, mitochondrial RNA polymerase (mtRNAP or POLRMT) and mitochondrial transcription factor A (mtTFA or TFAM), are key components of the core mitochondrial transcription apparatus. Structural information for POLRMT and TFAM from humans is available; however, there is no available structure for TFB2M. In the present study, three-dimensional structure of TFB2M from humans was modeled using a combination of homology modeling and small-angle X-ray scattering (SAXS). The TFB2M structural model adds substantively to our understanding of TFB2M function. An explanation for the low or absent RNA methyltransferase activity is provided. A putative nucleic acid-binding site is revealed. The amino and carboxy termini, while likely lacking defined secondary structure, appear to adopt compact, globular conformations, thus "capping" the ends of the protein. Finally, sites of interaction of TFB2M with other factors, protein and/or nucleic acid, are suggested by the identification of species-specific clusters on the surface of the protein.

Addition of a Sagittal Cervical Posture Corrective Orthotic Device to a Multimodal Rehabilitation Program Improves Short- and Long-Term Outcomes in Patients With Discogenic Cervical Radiculopathy.

OBJECTIVE: To investigate the immediate and 1-year effects of a multimodal program, with cervical lordosis and anterior head translation (AHT) rehabilitation, on the intensity of pain, disability, and peripheral and central nervous system function in patients with discogenic cervical radiculopathy (CR). DESIGN: A randomized controlled trial with 1-year and 10-week follow-up. SETTING: University research laboratory. PARTICIPANTS: Patients (N=60; 27 men) with chronic discogenic CR, a defined hypolordotic cervical spine, and AHT posture were randomly assigned to a control group (n=30; mean age, 43.9±6.2y) or an intervention group (n=30; mean age, 41.5±3.7y). INTERVENTIONS: Both groups received the multimodal program; in addition, the intervention group received the Denneroll cervical traction device. MAIN OUTCOME MEASURES: AHT distance, cervical lordosis, arm pain intensity, neck pain intensity, and disability (Neck Disability Index [NDI]), dermatomal somatosensory evoked potentials (DSSEPs), and central somatosensory conduction time (N13-N20). Measures were assessed at 3 time intervals: baseline, 10 weeks, and 1-year follow-up. RESULTS: After 10 weeks of treatment, between-group analysis showed equal improvement in arm pain intensity (P=.40), neck pain intensity (P=.60), and latency of DSSEPs (P=.60) in both intervention and control groups. However, also at 10 weeks, there were significant differences between groups, favoring the intervention group for cervical lordosis (P<.0005), AHT distance (P<.0005), amplitude of DSSEPs (P<.0005), N13 to N20 conduction time (P<.0005), and NDI (P<.0005). Although at 1-year follow-up, between-group analysis identified a regression back to baseline values for the control group. Thus, all variables were significantly different, favoring the intervention group at 1-year follow-up: cervical lordosis (P<.0005), AHT distance (P<.0005), latency and amplitude of DSSEPs (P<.0005), N13 to N20 conduction time (P<.0005), intensity of neck and arm pain, and NDI (P<.0005). CONCLUSIONS: The addition of the Denneroll cervical orthotic device to a multimodal program positively affected discogenic CR outcomes at long-term follow-up. We speculate that improved cervical lordosis and reduced AHT contributed to our findings.

Structural dynamics as a contributor to error-prone replication by an RNA-dependent RNA polymerase.

RNA viruses encoding high- or low-fidelity RNA-dependent RNA polymerases (RdRp) are attenuated. The ability to predict residues of the RdRp required for faithful incorporation of nucleotides represents an essential step in any pipeline intended to exploit perturbed fidelity as the basis for rational design of vaccine candidates. We used x-ray crystallography, molecular dynamics simulations, NMR spectroscopy, and pre-steady-state kinetics to compare a mutator (H273R) RdRp from poliovirus to the wild-type (WT) enzyme. We show that the nucleotide-binding site toggles between the nucleotide binding-occluded and nucleotide binding-competent states. The conformational dynamics between these states were enhanced by binding to primed template RNA. For the WT, the occluded conformation was favored; for H273R, the competent conformation was favored. The resonance for Met-187 in our NMR spectra reported on the ability of the enzyme to check the correctness of the bound nucleotide. Kinetic experiments were consistent with the conformational dynamics contributing to the established pre-incorporation conformational change and fidelity checkpoint. For H273R, residues comprising the active site spent more time in the catalytically competent conformation and were more positively correlated than the WT. We propose that by linking the equilibrium between the binding-occluded and binding-competent conformations of the nucleotide-binding pocket and other active-site dynamics to the correctness of the bound nucleotide, faithful nucleotide incorporation is achieved. These studies underscore the need to apply multiple biophysical and biochemical approaches to the elucidation of the physical basis for polymerase fidelity.

The addition of upper cervical manipulative therapy in the treatment of patients with fibromyalgia: a randomized controlled trial.

The aim of this study was to investigate the immediate and long-term effects of a one-year multimodal program, with the addition of upper cervical manipulative therapy, on fibromyalgia management outcomes in addition to three-dimensional (3D) postural measures. This randomized clinical trial with one-year follow-up was completed at the research laboratory of our university. A total of 120 (52 female) patients with fibromyalgia syndrome (FMS) and definite C1-2 joint dysfunction were randomly assigned to the control or an experimental group. Both groups received a multimodal program; additionally, the experimental group received upper cervical manipulative therapy. Primary outcomes were the Fibromyalgia Impact Questionnaire (FIQ), whereas secondary outcomes included Pain Catastrophizing Scale (PCS), algometric score, Pittsburgh Sleep Quality Index (PSQI), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and 3D postural measures. Measures were assessed at three time intervals: baseline, 12 weeks, and 1 year after the 12-week follow-up. The general linear model with repeated measures indicated a significant group × time effect in favor of the experimental group on the measures of 3D postural parameters (P < .0005), FIQ (P < .0005), PCS (P < .0005), algometric score (F = P < .0005), PSQI (P < .0005), BAI (P < .0005), and BDI (P < .0005). The addition of the upper cervical manipulative therapy to a multimodal program is beneficial in treating patients with FMS.

Transcription from the second heavy-strand promoter of human mtDNA is repressed by transcription factor A in vitro.

Cell-based studies support the existence of two promoters on the heavy strand of mtDNA: heavy-strand promoter 1 (HSP1) and HSP2. However, transcription from HSP2 has been reported only once in a cell-free system, and never when recombinant proteins have been used. Here, we document transcription from HSP2 using an in vitro system of defined composition. An oligonucleotide template representing positions 596-685 of mtDNA was sufficient to observe transcription by the human mtRNA polymerase (POLRMT) that was absolutely dependent on mitochondrial transcription factor B2 (TFB2M). POLRMT/TFB2M-dependent transcription was inhibited by concentrations of mitochondrial transcription factor A (TFAM) stoichiometric with the transcription template, a condition that activates transcription from the light-strand promoter (LSP) in vitro. Domains of TFAM required for LSP activation were also required for HSP2 repression, whereas other mtDNA binding proteins failed to alter transcriptional output. Binding sites for TFAM were located on both sides of the start site of transcription from HSP2, suggesting that TFAM binding interferes with POLRMT and/or TFB2M binding. Consistent with a competitive binding model for TFAM repression of HSP2, the impact of TFAM concentration on HSP2 transcription was diminished by elevating the POLRMT and TFB2M concentrations. In the context of our previous studies of LSP and HSP1, it is now clear that three promoters exist in human mtDNA. Each promoter has a unique requirement for and/or response to the level of TFAM present, thus implying far greater complexity in the regulation of mammalian mitochondrial transcription than recognized to date.

The effect of adding forward head posture corrective exercises in the management of lumbosacral radiculopathy: a randomized controlled study.

OBJECTIVE: The purpose of this study was to determine the immediate and long-term effects of a multimodal program, with the addition of forward head posture correction, in patients with chronic discogenic lumbosacral radiculopathy. METHODS: This randomized clinical study included 154 adult patients (54 females) who experienced chronic discogenic lumbosacral radiculopathy and had forward head posture. One group received a functional restoration program, and the experimental group received forward head posture corrective exercises. Primary outcomes were the Oswestry Disability Index (ODI). Secondary outcomes included the anterior head translation, lumbar lordosis, thoracic kyphosis, trunk inclination, lateral deviation, trunk imbalance, surface rotation, pelvic inclination, leg and back pain scores, and H-reflex latency and amplitude. Patients were assessed at 3 intervals (pretreatment, 10-week posttreatment, and 2-year follow-up). RESULTS: A general linear model with repeated measures indicated a significant group × time effect in favor of the experimental group on the measures of ODI (F = 89.7; P < .0005), anterior head translation (F = 23.6; P < .0005), H-reflex amplitude (F = 151.4; P < .0005), H-reflex latency (F = 99.2; P < .0005), back pain (F = 140.8; P < .0005), and leg pain (F = 72; P < .0005). After 10 weeks, the results revealed an insignificant difference between the groups for ODI (P = .08), back pain (P = .29), leg pain (P = .019), H-reflex amplitude (P = .09), and H-reflex latency (P = .098). At the 2-year follow-up, there were significant differences between the groups for all variables adopted for this study (P < .05). CONCLUSIONS: The addition of forward head posture correction to a functional restoration program seemed to positively affect disability, 3-dimensional spinal posture parameters, back and leg pain, and S1 nerve root function of patients with chronic discogenic lumbosacral radiculopathy.

Vaccine-derived mutation in motif D of poliovirus RNA-dependent RNA polymerase lowers nucleotide incorporation fidelity.

All viral RNA-dependent RNA polymerases (RdRps) have a conserved structural element termed motif D. Studies of the RdRp from poliovirus (PV) have shown that a conformational change of motif D leads to efficient and faithful nucleotide addition by bringing Lys-359 into the active site where it serves as a general acid. The RdRp of the Sabin I vaccine strain has Thr-362 changed to Ile. Such a drastic change so close to Lys-359 might alter RdRp function and contribute in some way to the attenuated phenotype of Sabin type I. Here we present our characterization of the T362I RdRp. We find that the T362I RdRp exhibits a mutator phenotype in biochemical experiments in vitro. Using NMR, we show that this change in nucleotide incorporation fidelity correlates with a change in the structural dynamics of motif D. A recombinant PV expressing the T362I RdRp exhibits normal growth properties in cell culture but expresses a mutator phenotype in cells. For example, the T362I-containing PV is more sensitive to the mutagenic activity of ribavirin than wild-type PV. Interestingly, the T362I change was sufficient to cause a statistically significant reduction in viral virulence. Collectively, these studies suggest that residues of motif D can be targeted when changes in nucleotide incorporation fidelity are desired. Given the observation that fidelity mutants can serve as vaccine candidates, it may be possible to use engineering of motif D for this purpose.

Impact of the Order of Movement on the Median Nerve Root Function: A Neurophysiological Study with Implications for Neurodynamic Exercise Sequencing.

Background: Neurodynamic exercise is a common clinical practice used to restore neural dynamic balance. The order in which movements are performed during these exercises is believed to play a crucial role in their effectiveness. This study aimed to investigate the impact of different sequences of neurodynamic exercise on nerve root function, with a specific focus on the median nerve. Methods: Participants were assigned randomly to three experimental groups, each undergoing a different test sequence: standard, proximal-to-distal, and distal-to-proximal. Dermatomal somatosensory evoked potentials (DSSEPs) were recorded at key levels (C6, C7, C8, and T1). Results: The findings revealed a significant influence of the movement sequence on DSSEP amplitudes. The execution of neurodynamic exercise in the proximal-to-distal sequence was associated with a notable reduction in amplitudes (p < 0.05). Conversely, the distal-to-proximal sequence resulted in increased amplitudes compared to the standard sequence (p < 0.05). Conclusions: This study underscores the importance of carefully considering the order of movements during neurodynamic exercising, particularly when evaluating nerve roots that lack the protective perineurium. The choice of sequence appears to have a substantial impact on nerve function, with implications for optimizing clinical neurodynamic exercise techniques.

Two Methods of Forward Head Posture Assessment: Radiography vs. Posture and Their Clinical Comparison.

Background: Forward head posture (FHP) and altered cervical lordotic curvatures are common spine displacements often associated with neck pain and disability. Two primary categories for determining FHP exist: radiographic and postural measurements. Methods: This study investigated the correlation between the craniovertebral angle (CVA), the radiographically measured C2-C7 sagittal vertical axis (SVA), and cervical lordosis (absolute rotation angle: ARA C2-C7) in a sample of participants with chronic myofascial pain (CMP). In 120 participants, we performed both a postural measurement of the CVA and a lateral cervical radiograph, where the C2-C7 SVA and ARA C2-C7 were measured. A linear-regression R2 value to assess the correlation between the CVA, C2-C7 SVA, and ARA C2-C7 was sought. Results: A statistically significant weak linear fit was identified (Spearman's r = 0.549; R2 = 0.30, p < 0.001) between the CVA and C2-C7 SVA, having considerable variation between the two measures. A statistically significant linear fit (very weak) was identified for the lordosis ARA C2-C7 and the CVA: Spearman's r = 0.524; R2 = 0.275; p < 0.001. A value of 50° for the CVA corresponded to a value of 20 mm for the C2-C7 SVA on an X-ray. Conclusion: While the CVA and radiographic C2-C7 SVA are weakly correlated in an individual, they seem to represent different aspects of sagittal cervical balance. The CVA cannot replace radiographically measured cervical lordosis. We recommend that more emphasis be given to radiographic measures of sagittal cervical alignment than the CVA when considering patient interventions.